1. Field of the Invention
The present invention relates to a brake control device which is installed in a railway vehicle and operates an air brake.
Priority is claimed on Japanese Patent Application No. 2011-262822, filed Nov. 30, 2011, the contents of which are incorporated herein by reference.
2. Description of the Related Art
Conventionally, there is known a brake control device for a railway vehicle, comprising as a brake system for service operation; a pressure control section which outputs a brake command signal (electric signal), a solenoid valve which outputs a brake command pressure (air pressure) proportional to the brake command signal, and a relay valve which, using the brake command pressure output by the solenoid valve as a control pressure, applies amplification accordingly and outputs the resulting air pressure to a brake cylinder. As a brake system for emergency operation, the brake system comprises a variable load valve which detects pressure variation in proportion to the total weight of the vehicle including movable load such as passengers and cargo, and provides this detected output to the relay valve after amplification via a solenoid valve.
Typically, because the space for mounting the brake control device on the vehicle is limited, there is a problem in how to reduce the size of the device while still maintaining its performance. Thus, respective valves including solenoid valves, relay valves, double check valves, and variable load valves are organized into related groups, each group is installed on a block, and the plurality of solenoid valves are wired to a controller (refer for example to Japanese Patent No. 4310149 and Japanese Patent No. 4485347).
However, in the brake control device described above, the plurality of solenoid valves are interspersed throughout the device. Therefore, there is a problem of wiring because wiring required from each sensor to the controller, and moreover, complex wiring from the solenoid valves to the controller is required in the vicinity of components such as the valve blocks.